managing battery usage

[elmonsanto]

We picked up our A122S at the end of March and camped three nights in Oregon before returning to San Francisco. We had shore power the whole time and really enjoyed how warm and cozy it was. Now we have to learn the best way for us to dry camp in California. We understand that we need to stay within our "electrical budget" while still being comfortable. I've read all the forum posts on the subject but still have some questions.

We have two 6-volt batteries in series for a total of 232 amp-hours when fully charged. Any appliances we run will obviously subtract amp-hours from the batteries. We need to know how much current (amps) is being drawn from the batteries under different conditions of appliance use so we can maximize our battery usage. After reading "Managing 12 Volts" by Harold Barr, I understand the maximum current we should be drawing is 232 amp-hours divided by 20 hours is 11.6 amps. Do I have this right?

1. Is there any way to directly measure the number of amps being drawn from the batteries? Right now, the only thing I know how to measure directly is the battery voltage.

2. Where can I find the number of amps that appliances like the furnace fan and the fantastic fan draw? I could use the information to get a rough estimate of the number of amps we're drawing.

Thanks!

[RenoRock]

We installed a TriMetric 2025RV battery monitor. When you're on battery power you can see your current amp draw. Turn on/off an appliance and you'll see the number increase/decrease. It was pretty easy to install and it has the added benefit of showing the battery percentage available to use as well as letting us know exactly when the battery is once again fully charged so we don't have to run the generator any more than is necessary to refill the bank. TriMetric Battery Monitor

[D-mo]

Sounds like your well on your way for battery use. Some of us here (Aframe) have installed dual batteries with some solar. You can do a search of this forum for conversations concerning the use of various appliances .. .but in summary .. the only big users are the propane heater fan and waterpump .. and maybe the lights.
We have had great success with a good quality 80 watt solar panel, tied into two group 31 12volters. Both batteries top up the same day of charging.
Your Fantanstic Fan may pull about .4 amps an hour/on low... the water pump is much bigger .. .but who really uses that .. that much during the day .. maybe a minute or two???...but thats all i really know .. as we keep the fantasic fan unit on all the time we are camping .. wheither we are in or out of the unit. Lights are another thing .. but we have yet to change out the bulbs to LEDS due to safety issues that our friends expencied ... and use them like we are at home.
All in all .. check your battery once a day to see the voltage draw ...

d-mo

[daveinpickerington]

The Trimetric is really nice. I didn't want to spend that much, so I purchased the Watts Up meter. It's small and handy to use in many different locations.

DC Inline Watt Meter and Power Analyzer, Powerpole Ends [WattMeter-PP] - $59.99

Watt's Up Meter by Power Werx

[elmonsanto]

Originally Posted by daveinpickerington

The Trimetric is really nice. I didn't want to spend that much, so I purchased the Watts Up meter. It's small and handy to use in many different locations.

It's great to hear that you use a Watt's Up Meter since I've been using one for years with my ham radio. Where do you connect the meter and what kind of connectors do you use? For my radio, I use PowerPoles to connect the meter directly between a 7 amp-hour battery and my radio but I can't figure out where to install the meter on the A122S. Hopefully, I'm missing the obvious.

Thanks!

[daveinpickerington]

Originally Posted by elmonsanto

It's great to hear that you use a Watt's Up Meter since I've been using one for years with my ham radio. Where do you connect the meter and what kind of connectors do you use? For my radio, I use PowerPoles to connect the meter directly between a 7 amp-hour battery and my radio but I can't figure out where to install the meter on the A122S. Hopefully, I'm missing the obvious.

Thanks!

Mine is installed in my add-on battery compartment.

Solar Panel on A122 Travel Trailer - Part 2 - YouTube

Find where the 12V comes into the trailer behind the converter. Place it in series with the wiring and mount the meter in the area to the left of the converter cover. Perhaps where my cig lighter/power pole panel is located in the following vid.

Interior 12V Wiring for A122 Travel Trailer - YouTube

Dave